The present invention relates, in general to hand brake assemblies for use on railway type vehicles and, more particularly to a pneumatically and/or electrically activated control apparatus for activating a hand brake assembly on a railway vehicle. The apparatus of the present invention is also capable of pneumatically or electrically releasing the hand brake assembly on the railway vehicle.
Prior to the conception and development of the present invention, railway car hand brake mechanisms were well known in the art. They usually include a large, rotatable hand wheel disposed in a vertical plane and mounted on a shaft which, through a gear train, can rotate a chain drum to wind up a chain that is secured at its end remote from the chain drum to the brake rigging of the railway car. As the hand wheel is rotated in one direction, the brakes are applied and rotation of the hand wheel shaft in the opposite direction is prevented by a pawl which engages a detent wheel on the hand wheel shaft. The hand wheel is rotated manually and requires an operator to apply a sufficient amount of force thereto.
The brakes may be released by disengaging the pawl from the detent wheel by manually turning the hand wheel in an opposite direction, however this may cause rapid rotation of the hand wheel which may cause a hazardous condition. To avoid rapid rotation of the hand wheel, hand brake mechanisms have been devised which are known as xe2x80x9cquick releasexe2x80x9d mechanisms. Generally these quick release mechanisms include a releasable connecting means between the hand wheel shaft and the gear train. When the connecting means is released, the gears of the gear train rotate rapidly, without constraint by the pawl and detent wheel, but the hand wheel remains stationary.
As can be seen from the above-discussion, it would be advantageous to have an automatic application apparatus controlled by a pneumatic or electronic system for applying the hand brake and releasing the hand brake. Such a system would thereby reduce the force required to apply the brakes and avoid a hazardous condition upon the release of the brakes. Such automatic application apparatus is the subject of a co-pending application Ser. No. 09/507,227, filed Feb. 18, 2000 entitled Automatic Application Hand Brake. This co-pending application is owned by the assignee of the present invention and is incorporated into the present application by reference thereto.
According to a first aspect, the present invention is directed to an apparatus engageable with a hand brake assembly on a railway vehicle for operation of an application cylinder for applying the hand brake assembly. This apparatus comprises a source of fluid pressure which is engageable with the railway vehicle. A pneumatic actuation valve is connected to this source of fluid pressure for initiating communication of fluid pressure from the source of fluid pressure. A force regulating valve is connected to the pneumatic actuation valve for receiving the fluid pressure from the actuation valve and a mechanically driven valve is connected to the force regulating valve for receiving the fluid pressure from the force regulating valve and for communicating the fluid pressure to the application cylinder to apply the hand brake assembly.
In a second aspect of the invention, an electrically controlled valve may be positioned intermediate the source of fluid pressure and the force regulating valve to enable electronic actuation of fluid communication from the source of fluid pressure to the force regulating valve.
Additionally, a pneumatic actuation valve and/or an electrically controlled actuation valve may be provided to communicate fluid pressure from a source of fluid pressure to a release cylinder in order to release the brakes of the hand brake assembly.
It is, therefore, a primary object of the invention to provide a control apparatus for applying the hand brake assembly on a railway vehicle.
Another object is to provide a control apparatus which is capable of releasing the hand brake assembly of the railway vehicle.
Yet another object is to provide a control apparatus which is capable of applying and/or releasing the hand brake assembly of the railway vehicle through the use of a pneumatic actuation valve.
Still yet another object is to provide a control apparatus which is capable of applying and/or releasing the hand brake assembly of the railway vehicle through the use of an electrically controlled actuation valve.
Another object is to provide a control apparatus engageable with a hand brake assembly which applies and/or releases the hand brake assembly on a railway vehicle without requiring an operator to manually wind and/or unwind the chain on the hand brake.
Yet another object is to provide a control apparatus which releases hand brake assembly on a railway vehicle without requiring an operator to manually release the quick release handle.
Still another object is to provide a control apparatus engageable with a hand brake assembly which may be used by an operator of basically any physical size or stature.
An even further object is to provide a control apparatus engageable with a hand brake assembly which will provide the necessary torque to set such hand brake properly and will substantially minimize the possibility of an operator improperly setting the hand brake by not applying enough torque or conversely by applying too much torque which could damage the brake rigging.
In addition to the several objects and advantages of the present invention generally described above, various other objects and advantages of the invention will become much more readily apparent to those persons who are skilled in the relevant art from the following more detailed description, particularly, when such detailed description is taken in conjunction with the attached drawing figures and the claims appended hereto.